General Motors 4.3L GM Engine — Electronic Pressure Regulator (EPR) Removal/Installation
Repair & overhaul
For the General Motors 4.3L GM Engine, from the General Motors service manual.
Before you start
- Do not use Teflon tape on any fuel fitting - use liquid pipe thread sealant.
Procedure
- Relieve the LPG fuel system pressure; disconnect the negative battery cable.
- Disconnect the LPG fuel inlet line from the Shut-Off Valve fitting.
- Disconnect the EPR electrical connector.
- Clamp both coolant lines near the EPR fittings.
- Remove retaining pins from water inlet/outlet fittings, fuel hose and Temperature Sensor.
- Remove coolant inlet and outlet fittings, fuel hose and Temperature Sensor.
- Remove the four bolts attaching the EPR bracket and adapter to the intake manifold.
- Remove EPR, EPR bracket, Lock-Off Connector bracket and Shut-Off Valve assembly.
- Remove screw from top of Shut-Off Valve and remove coil; remove electrical connector from Lock-Off bracket.
- Remove Shut-Off Valve from EPR with brass fittings as a single assembly.
- Remove three nuts securing vibration mounts to EPR mounting bracket; remove vibration mounts and Lock-Off bracket.
Tools required
- Loctite 567 or equivalent high-temp thread locker/sealer Amazon
Tool links are Amazon searches (affiliate links); manufacturer special tools may only be available from a dealer.
Specs & values
- EPR to upper bracket bolts 15 N·m (11 ft. lbs.); EPR fuel inlet line 27 N·m (20 ft. lbs.)
Source: General Motors service manual. Steps and values are as documented; always cross-check against the official manual and any later revisions for your exact serial number before servicing.